1. Field of Invention
The present invention relates to a motor and a control circuit thereof and in particular to a motor controlled by multiple sensor chips and a control circuit thereof.
2. Related Art
FIG. 1 is a schematic illustration showing a conventional motor 1. Referring to FIG. 1, the motor 1 has a rotor 11 and a stator 12. The rotor 11 has many magnetic poles including two N poles and two S poles arranged alternately. The stator 12 is composed of a plurality of silicon steel sheets stacked together, and the stator 12 has a plurality of winding sensing arms disposed opposite to the magnetic poles.
FIG. 2 is a schematic illustration showing a control circuit 13 of the motor 1 of FIG. 1. Referring to FIG. 2, the control circuit 13 includes a sensor chip 131 and a winding set 132. The sensor chip 131 of the control circuit 13 has a positive power input terminal V+ and a negative power input terminal V−, the positive power input terminal V+ is electrically connected to a positive power VCC, and the negative power input terminal V− is electrically connected to a ground Vground. In addition, the sensor chip 131 has two output ports A and B. The winding set 132 has a first winding L1 and a second winding L2, which are respectively electrically connected to the output ports A and B.
The sensor chip 131 senses magnetic properties of the magnetic poles of the rotor to change the directions of the currents flowing through the first winding L1 and the second winding L2 to make the winding sensing arms generate magnetic forces to push the rotor 11 to rotate.
As mentioned above, one control circuit for controlling the conventional motor only has a sensor chip. Thus, one sensor chip needs to control the winding sets of the whole motor to provide the currents for the windings. Because the typical sensor chip cannot withstand the extra high current, this control circuit cannot be applied to the motor having high rotating speed, or the large size motor. Thus, the sensor chip for controlling the motor having the high rotating speed, or the large size motor must have the higher current withstanding ability, and this sensor chip usually has the higher cost.